A gateway is a network point that acts as an entrance to another network. Secure communications between different networks may be conducted using a virtual private network (VPN). A typical VPN is a network of point-to-point tunnels, where each tunnel is a security association (SA) between two security devices. A security key for the SA is negotiated between two tunnel end devices.
Secure gateway architecture to support VPNs typically involves dedicated physical devices for enterprise clients. Scaling this dedicated secure gateway architecture for a multitenant environment that is suitable for service providers is both costly and subject to time-to-market delays.